Analysis:
========
Increasing the length of the indexed varchar column is not an instant operation for
innodb.
Fix:
===
- Introduce the new handler flag 'Alter_inplace_info::ALTER_COLUMN_INDEX_LENGTH' to
indicate the index length differs due to change of column length changes.
- InnoDB makes the ALTER_COLUMN_INDEX_LENGTH flag as instant operation.
This is a port of Mysql fix.
commit 913071c0b16cc03e703308250d795bc381627e37
Author: Nisha Gopalakrishnan <nisha.gopalakrishnan@oracle.com>
Date: Wed May 30 14:54:46 2018 +0530
BUG#26848813: INDEXED COLUMN CAN'T BE CHANGED FROM VARCHAR(15)
TO VARCHAR(40) INSTANTANEOUSLY
Bootstrap in a separate thread was introduced in 746f0b3b7 to workaround
OS/2 small stack size. OS/2 support was discontinued in 2006 and modern
operating systems have default stack size a few times larger than
default thread_stack and it is tunable.
Aim is to reduce usage of LOCK_thread_count and COND_thread_count.
Part of MDEV-15135.
Problem:
========
Server fails to notify the engine by not setting the ADD_PK_INDEX and
DROP_PK_INDEX When there is a
i) Change in candidate for primary key.
ii) New candidate for primary key.
Fix:
====
Server sets the ADD_PK_INDEX and DROP_PK_INDEX while doing alter for the
above problematic case.
The error message modified.
Then the TABLE_SHARE::error_table_name() implementation taken from 10.3,
to be used as a name of the table in this message.
Alter statement changed the THD structure by setting the value to FIELD_CHECK_WARN
and then not resetting it back. This led ANALYZE to throw a warning which previously
it didn't.
Part of MDEV-5336 Implement LOCK FOR BACKUP
- Changed check of Global_only_lock to also include BACKUP lock.
- We store latest MDL_BACKUP_DDL lock in thd->mdl_backup_ticket to be able
to downgrade lock during copy_data_between_tables()
Part of MDEV-5336 Implement LOCK FOR BACKUP
- Added new locks to MDL_BACKUP for all stages of backup locks and
a new MDL lock needed for backup stages.
- Renamed MDL_BACKUP_STMT to MDL_BACKUP_DDL
- flush_tables() takes a new parameter that decides what should be flushed.
- InnoDB, Aria (transactional tables with checksums), Blackhole, Federated
and Federatedx tables are marked to be safe for online backup. We are
using MDL_BACKUP_TRANS_DML instead of MDL_BACKUP_DML locks for these
which allows any DML's to proceed for these tables during the whole
backup process until BACKUP STAGE COMMIT which will block the final
commit.
- Call delete_statistics_tables() after lock_table_names in drop tables.
This avoids a deadlock issue with FTWRL and future backup locks.
- Added some missing clear_error()
- Ensure we don't clear error caused by the caller
- Updated function comments
- The old code used the original create_info from lex, not the new one
that includes more information (like OPT_OR_REPLACE).
The bug was not discovered as the code in lock_table_named() only
checked for OPT_OR_REPLACE in case of timeout errors.
As lock_table_names will be fixed as part of BACKUP STAGE's, there
is no changes in lock_table_names() in this commit.
- Removed also the 'temporary' copy of statement flags to thd for
lock_table_names()
We don't have many bits left, no need to add another InnoDB-specific flag.
Instead, we say that HA_REQUIRE_PRIMARY_KEY does not apply to SEQUENCE.
Meaning, if the engine declares HA_CAN_TABLES_WITHOUT_ROLLBACK (required
for SEQUENCE) it *must* support tables without a primary key.
Fixed by adding table flag HA_WANTS_PRIMARY_KEY, which is like
HA_REQUIRE_PRIMARY_KEY but tells SQL upper layer that the storage engine
internally can handle tables without primary keys (for example for
sequences or trough user variables)
Locked_tables_list::unlock_locked_tables
Similarly to regular DROP TABLE, don't leave locked tables mode if CREATE OR
REPLACE dropped temporary table but failed to cerate new one.
The problem is that there's no track of which temporary table was "locked" by
LOCK TABLES.
ALTER TABLE locks the table with TL_READ_NO_INSERT, to prevent the
source table modifications while it's being copied. But there's an
indirect way of modifying a table, via cascade FK actions.
After previous commits, an attempt to modify an FK parent table
will cause FK children to be prelocked, so the table-being-altered
cannot be modified by a cascade FK action, because ALTER holds a
lock and prelocking will wait.
But if a new FK is being added by this very ALTER, then the target
table is not locked yet (it's a temporary table). So, we have to
lock FK parents explicitly.
Problem was that the number of NULL bit's was record wrong in the
.frm file because there could be more fields marked NOT_NULL after the
number of not_null fields where recorded.
Fixed by copying test for virtual fields from prepare_create_field()
The code change, only the test, doesn't have to be merged to 10.3
as this is fixed there.
Make all system tables in mysql directory of type
engine=Aria
Privilege tables are using transactional=1
Statistical tables are using transactional=0, to allow them
to be quickly updated with low overhead.
Help tables are also using transactional=0 as these are only
updated at init time.
Other changes:
- Aria store engine is now a required engine
- Update comment for Aria tables to reflect their new usage
- Fixed that _ma_reset_trn_for_table() removes unlocked table
from transaction table list. This was needed to allow one
to lock and unlock system tables separately from other
tables, for example when reading a procedure from mysql.proc
- Don't give a warning when using transactional=1 for engines
that is using transactions. This is both logical and also
to avoid warnings/errors when doing an alter of a privilege
table to InnoDB.
- Don't abort on warnings from ALTER TABLE for changes that
would be accepted by CREATE TABLE.
- New created Aria transactional tables are marked as not movable
(as they include create_rename_lsn).
- bootstrap.test was changed to kill orignal server, as one
can't anymore have two servers started at same time on same
data directory and data files.
- Disable maria.small_blocksize as one can't anymore change
aria block size after system tables are created.
- Speed up creation of help tables by using lock tables.
- wsrep_sst_resync now also copies Aria redo logs.
- Adding a helper class Sec6 to store (neg,seconds,microseconds)
- Adding a helper class VSec6 (Sec6 with a flag for "IS NULL")
- Wrapping related functions as methods of Sec6;
* number_to_datetime()
* number_to_time()
* my_decimal2seconds()
* Item::get_seconds()
* A big piece of code in Item_func_sec_to_time::get_date()
- Using the new classes in places where second-to-temporal
conversion takes place:
* Field_timestamp::store(double)
* Field_timestamp::store(longlong)
* Field_timestamp_with_dec::store_decimal(my_decimal)
* Field_temporal_with_date::store(double)
* Field_temporal_with_date::store(longlong)
* Field_time::store(double)
* Field_time::store(longlong)
* Field_time::store_decimal(my_decimal)
* Field_temporal_with_date::store_decimal(my_decimal)
* get_interval_value()
* Item_func_sec_to_time::get_date()
* Item_func_from_unixtime::get_date()
* Item_func_maketime::get_date()
This change simplifies these methods and functions a lot.
- Warnings are now sent at VSec6 initialization time, when the source
data is available in its original data type representation.
If Sec6::to_time() or Sec6::to_datetime() truncate data again during
conversion to MYSQL_TIME, they send warnings, but only if no warnings
were sent during VSec6 initialization. This helps prevents double warnings.
The call for val_str() in Item_func_sec_to_time::get_date() is not
needed any more, so it's removed. This change actually fixes the problem.
As a good effect, FROM_UNIXTIME() and MAKETIME() now also send warnings
in case if the seconds arguments is out of range. Previously these
functions returned NULL silently.
- Splitting the code in the global function make_truncated_value_warning()
into a number of methods THD::raise_warning_xxxx().
This was needed to reuse the logic that chooses between:
* ER_TRUNCATED_WRONG_VALUE
* ER_WRONG_VALUE
* ER_TRUNCATED_WRONG_VALUE_FOR_FIELD
for non-temporal data types (Sec6).
- Removing:
* Item::get_seconds()
* number_to_time_with_warn()
as this code now resides inside methods of Sec6.
- Cleanup (changes that are not directly related to the fix):
* Removing calls for field_name_or_null() and passing NULL instead
in Item_func_hybrid_field_type::get_date_from_{int|real}_op,
because Item_func_hybrid_field_type::field_name_or_null()
always returns NULL
* Replacing a number of calls for make_truncated_value_warning()
to calls for THD::raise_warning_xxx(). In these places
we know that the execution went through a certain
branch of make_truncated_value_warning(),
(e.g. the exact error code is known, or field name is always NULL,
or field name is always not-NULL). So calls for the entire
make_truncated_value_warning() after splitting are not necessary.
MEMORY table could be renamed into a non-extistent database.
rename() is documented to return ENOENT when the source file does not
exist OR when the target directory not exist. Nonexistent source .frm
file is ok (table can still exist in the engine), nonexistent target
directory is not.
Make my_rename to use ENOTDIR for the latter case. Make RENAME TABLE
issue an appropriate error ("unknown database" instead of "unknown table")
